Removable and adjustable surf fin system

ABSTRACT

A fin plug assembly to receive and engage a fin includes a cavity, a cam with gears, and a worm gear. The fin plug assembly allows a quick and easy fore-aft adjustment of the fin. Disclosed also is a method of installing the fin plug assembly in a surfboard using a one-piece complete control jig system including the step of providing additional structural strength by removing and/or spiking the foam material in the body of the surfboard.

1. RELATED APPLICATIONS

[0001] This application claims priority to a U.S. patent applicationSer. No. 09/990,919, filed Nov. 13, 2001, which is hereby incorporatedby reference into the application.

BACKGROUND OF THE INVENTION

[0002] 2. Field of the Invention

[0003] This invention relates to a removable and adjustable fin systemfor surfcraft such as surfboards, and a method for installing the finsystem on a surfboard.

[0004] 3. Related Art

[0005] In the manufacture of surfboards, a body of plastic foam materialis shaped and then covered with a layer of fiber-reinforced resin,normally fiberglass. The body of surfboards has an upper side or ridesurface for supporting a surfer and a lower surface that is directedinto the water. One or more fins, most commonly three, are fixed to thebody of the surfboard on the lower surface. The fins may be fixedpermanently to the board, for example, by utilizing fiber-reinforcedresin around the base of the fin.

[0006] There are, however, many disadvantages to permanently mounting afin to a surfboard in that the fin cannot be easily removed and replacedwhen the fin is damaged or when it is desirable to replace the fin withanother fin having different hydrodynamic performance properties.Further, it may be desirable to remove the fins to minimize thepotential for damage to the surfboard or to the fins during transportand storage. In order to accommodate removal and overcome thedisadvantages of permanent mounting, fin assembly systems that allowremoval of the fins from the surfboards have been developed. Suchremovable fin systems are disclosed, for example, in the U.S. Pat. Nos.5,328,397 and 5,975,974. The removable fin systems known in the art haveshortcomings, however, and there is room for improvement.

[0007] The existing fin systems require physical maneuvering, i.e.loosening of small grub screws, before the fins can be installed orremoved from the surfboard. Further, in most systems, an Allen key orother special tool is required and damage or corrosion of the grubscrews may make the removal and replacement process difficult and timeconsuming. In addition, existing systems do not provide for an easyadjustment of the fins once installed. It is often desirable to changethe fore-aft position of the fins, in particular, the rear or centerfin, depending on the surf conditions and the desired surfboardperformance. Current fin systems are designed for fixed or limitedpositions where the fins are inserted and secured, and provide no ordifficult adjustment capability to move the fins forward or backwardonce installed.

[0008] Other problems associated with existing systems relate to theinstallation of the fin fixing system into the body of the surfboards.The two-plug fixing system as described in the U.S. Pat. No. 5,328,397,for example, requires the accurate alignment of the plugs at apredetermined spacing of the plugs during the installation process. Anyslight offset of the plugs may result in a less than perfect alignmentof the plugs and could make it difficult or impossible to install thefins. The plugs could also lose alignment due to physical stress andtempering on the surfboards during the installation process. Further,the installation methods known in the art often require multiple markingand positioning jigs or templates and other tools and accessories, i.e.putty, tape, foam, center punch, etc. More significantly, conventionalinstallation methods typically involve multiple steps of marking,positioning, removal and repositioning of the jigs or templates, and areoften difficult and time-consuming. It would therefore be desirable tohave a complete control jig system that would allow an easy and accurateinstallation of a fin fixing system.

[0009] Therefore, there is a need for a, fin fixing system that allows aconvenient and quick installation, removal, and adjustment of the fins.An installation jig system that would allow an easy and accurateinstallation of a surf fin fixing system in a surfboard would also be auseful improvement.

BRIEF SUMMARY OF THE INVENTION

[0010] One of the features of the invention is to provide a fin plugassembly to be embedded in the body of a surfcraft such as a surfboardthat allows an easy installation, securing, and removal of a fin.Further, the fin plug assembly of the present invention allows an easyadjustment of the fore-aft positioning of the fin within the fin plugassembly.

[0011] In one embodiment, a fin plug assembly includes a cavity toreceive a fin and a cam adapted to rotate and secure the fin tab whenreceived in the cavity. The fin plug assembly includes a worm gearadapted to engage the teeth or gears of the cam which can be turnedusing a key, a screw driver, or any other device which can be insertedinto a slot in the worm gear and turn the worm gear. Further, the finplug assembly of the present invention allows the fore-aftmovement/positioning of the surf fin within the cavity by rotating thecam which is controlled by a simple turn of the worm gear. The fin plugassembly also allows a user to adjust the tightness of the fit betweenthe cam and the fin by controlling the degree or extent of the worm gearrotation.

[0012] Another aspect of the present invention is to provide a one-piececomplete control jig system which allows an easy and accurateinstallation of the fin plug assembly in a surfboard. The complete jigsystem includes a peel-off bottom portion which can be placed on andpreferably adheres to the surface of the surfboard where the fin plugassembly is to be installed. The complete jig system according to thepresent invention has a perforated and removable center portionproviding a template or guide for a trimmer, a router or other cuttingdevice to form a cavity in the surfboard into which the fin plugassembly can be mounted. The complete jig system also serves as a dam tohold resin poured to fix and hold the fin plug assembly. Preferably, thecomplete jig system also provides a plurality of removable tabs on whichthe outer supports or outriggers of the fin plug assembly may bepositioned during the installation process to properly align the finplug assembly with the surface of the surfcraft. The complete jig systemof the present invention is a one-piece multiple-function installationdevice which allows an easy, quick and accurate installation of the finplug assembly without having to utilize multiple jigs and other tools ofthe conventional systems.

[0013] Other systems, methods, features and advantages of the inventionwill be or will become apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention can be better understood with reference to thefollowing figures. The components in the figures are not necessarily toscale, emphasis instead being placed upon illustrating the principles ofthe invention. Moreover, in the figures, like reference numeralsdesignate corresponding parts throughout the different views.

[0015]FIG. 1 is an exemplary view illustrating how fins are installed infin plug assemblies on the lower surface of a surfboard according to oneembodiment of the present invention;

[0016]FIG. 2 is a cross sectional view of the fin plug assembly and thefin of FIG. 1 along the line 2-2 in FIG. 1;

[0017]FIG. 3 is a perspective top view of the fin plug assemblyaccording to one embodiment of the invention;

[0018]FIG. 4 is a cross sectional view of the fin plug assembly alongthe line 4-4 in FIG. 3 according to one embodiment of the presentinvention;

[0019]FIG. 5 is a cross sectional view of the fin plug assembly alongthe line 4-4 in FIG. 3 according to another embodiment of the presentinvention;

[0020]FIG. 6 is a cross sectional view of the fin plug assembly alongthe line 4-4 in FIG. 3 according to yet another embodiment of thepresent invention;

[0021]FIG. 7 is a perspective inside view of the fin plug assemblyaccording to one embodiment of the invention;

[0022]FIG. 8 is a perspective view of a complete jig system according toone embodiment of the invention;

[0023]FIG. 9 is another perspective view of the complete jig systemaccording to one embodiment of the invention; and

[0024]FIG. 10 is an exemplary view of the fin plug assemblies and acenter fin according to one embodiment of the present invention;

[0025]FIG. 11 is a cross sectional view of the surfboard and a mountingcavity formed therein according to one embodiment of the presentinvention;

[0026]FIG. 12 is a cross sectional view of a fin plug assembly engaginga tab with an undercut;

[0027]FIG. 13 is a cross sectional view of a fin plug assembly engaginga tab with a modified undercut;

[0028]FIG. 14 is a side view of a fin;

[0029]FIG. 15 is a bottom view of the fin;

[0030]FIG. 16 is a top view of a tab having corrugation inserted intothe cavity of a fin plug assembly;

[0031]FIG. 17 is a top view of a fin plug assembly engaging a tab;

[0032]FIG. 18 is a bottom view of a tab having a corrugation on thefront portion of the tab;

[0033]FIG. 19 is a bottom view of a tab having a corrugation on thebackside of the tab;

[0034]FIG. 20 is a bottom view of a tab having corrugation along certainportions of the tab;

[0035]FIG. 21 is a side view of a fin having corrugation along thelongitudinal axis of the tab;

[0036]FIG. 22 is a top view of a fin plug assembly where the tab of thefin and the cavity formed in the fin plug assembly engaging to lock inplace.

[0037]FIG. 23 is another embodiment of a fin plug assembly; and

[0038]FIG. 24 is still another embodiment of a fin plug assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] This description is not to be taken in a limiting sense, but ismade for the purpose of illustrating the general principles of theinvention. The section titles and overall organization of the presentdetailed description are for the purpose of convenience only and are notintended to limit the present invention.

[0040]FIG. 1 illustrates by way of example how fins 20, 30 are installedin a surfboard 22 using fin plug assemblies 24 of the present invention.FIG. 1 shows a lower surface 26 of a surfboard 22 which is received inthe water. The other side of the surfboard (not shown) is an upper ridesurface for supporting a surfer. A center or rear fin 30 as well as twoside fins 20 may be installed into the fin plug assemblies 24 (shown bydotted lines). The fin plug assemblies 24 for both the rear fin 30 andthe side fins 20 may have the same size, but typically the fin plugassembly 24 for the rear fin 30 is larger than the fin plug assemblies24 for the side fins 20 as shown in FIG. 1.

[0041] Generally, the side fins 20 and the rear fin 30 have an endsurface 32 and one or more tabs 34 extending from the end surface 32.The tab 34 is configured to be received in a cavity 40 of the fin plugassembly 24, and the side fin 20 or the rear fin 30 is secured withinthe fin plug assembly 24 by inserting a key 60 into a slot 64 (FIG. 3)of a worm gear 62 and turning the key 60. When the side fin 20 or therear fin 30 is properly installed, the end surface 32 preferably abutsagainst the fin plug assembly 24 and sits substantially flush with thelower surface 26 of the surfboard 22 and a top surface 74 (FIG. 3) ofthe fin plug assembly 24.

[0042] In FIG. 1, the rear fin 30 is depicted in a position at the farrear end of the cavity 40. However, by making the longitudinal length ofthe cavity 40 longer than that of the tab 34 of the rear fin 30, the fin30 may be moved and positioned fore and aft within the cavity 40. Thefore-aft movement/adjustment can be made quickly and easily, even in thesurf. The side fins 20 may also be moved and positioned fore and aftwithin the cavity 40 in the same manner as described above.

[0043] The fore-aft movement/adjustment is more clearly demonstratedwith reference to FIG. 2, which shows a cross-sectional view of the finplug assembly 24 and the rear fin 30 along the line 2-2 of FIG. 1. Inone embodiment of the present invention, the fin plug assembly 24 allowsthe fore-aft movement of the rear fin 30 up to around 15 mm. Thefore-aft movement of the side fins 20 is usually more restricted,allowing for displacement of only up to around 5 mm. The 5-15 mmmovement allowance is, however, not absolute and a greater or lesserallowance may be easily achieved by either making the cavity 40 longeror the tab 34 shorter.

[0044] The cross sectional view in FIG. 2 shows the rear fin 30 with thetab 34 received in the cavity 40. The end surface 32 of the fin may abutagainst and sit substantially flush with a portion of the lower surface26 of the surfboard 22 and the top surface 74 of the fin plug assembly24. As shown in FIG. 2, the rear fin 30 may be moved forward or backwardalong the direction indicated by the arrow 27, and the rear fin 30 maybe moved to the foremost position or anywhere between the fore and aftpositions, and locked in place.

[0045]FIG. 3 shows a perspective top view of the fin plug assembly 24according to one embodiment of the present invention. The fin plugassembly 24 is to be embedded into the surfboard 22 as shown in FIGS. 1and 2. As shown in FIG. 3, the fin plug assembly 24 has the cavity 40 toreceive the fin 20, 30, and a worm gear 62 with a generally rectangularshaped slot 64 to receive a key 60 (shown in FIG. 1). The fin plugassembly 24 in FIG. 3 is generally shaped as three overlappingcylinders, and has three temporary supports or outriggers 66 forpositioning the fin plug assembly 24 on the lower surface 26 of thesurfboard 22 during installation. The fin plug assembly 24 also has aplurality of recesses 70 and a collar 72 projecting upwardly from thetop surface 74 thereof around the peripheral edge of the fin plugassembly 24. The role of the outriggers 66, recesses 70 and the collar72 will be discussed in more detail hereinafter.

[0046] Different shapes, i.e. rectangular, oval, square, etc., for thefin plug assembly 24 may be used, and the three overlapping cylindershape of the fin plug assembly 24 is not meant to be restrictive orlimiting.

[0047] The details of the fin plug assembly 24 and the operation andinter-relationship between the worm gear 62 and an associated cam 80 areillustrated by an exemplary cross sectional view shown in FIG. 4. Theworm gear 62 is vertically aligned within the fin plug assembly 24. Theslot 64 of the worm gear 62 is substantially rectangular as shown, butit could be in any appropriate shape. The key 60, a screwdriver, a caror house key or other similarly shaped device may be inserted into theslot 64 to turn the worm gear 62.

[0048] Located within the fin plug assembly 24 is the cam 80 which ishorizontally placed and has gears or teeth 82. The cam 80 is adapted tofit with the worm gear 62 and rotate and engage the tab 34 of the fin20, 30. The term “horizontal” used herein refers to the alignment whichis longitudinally parallel to the cavity 40 of the fin plug assembly 24.

[0049] In the embodiment shown in FIGS. 3 and 4, turning the worm gear62 in the clockwise direction is designed to rotate the cam 80 to holdor engage the tab 34 of the fin 20, 30 inserted into the cavity 40,while turning the worm gear 62 in the counter-clockwise direction allowsthe cam 80 to disengage the tab 34 of the fin 20, 30 from the fin plugassembly 24.

[0050] As illustrated in FIG. 4, the fin plug assembly 24 includes alower part 42 and an upper part 44, which are as a final product sealedtogether using an ultrasonic welding process or other methods well knownin the art. Positioned in the fin plug assembly 24 is the worm gear 62having a plurality of gears or teeth 68, and the worm gear 62 isvertically placed within the fin plug assembly 24 as shown in FIG. 4.The upper part 44 and the lower part 42 of the fin plug assembly 24 forma built in bearing 46 which is adapted to receive the cam 80. The cam 80is positioned in the bearing 46 between the worm gear 62 and the cavity40. The cam 80 has a plurality of matching gears or teeth 82 to fit withthe gears 68 of the worm gear 62. The cam 80 has a flat or disengagingportion 84 and a bulging or engaging portion 86.

[0051] The cam 80 is generally circular in shape except in the flatportion 84 and in the region where the gears 82 are positioned. Thephrase “bulging portion” used herein refers to the generally circularportion of the cam 80 which is aligned with and engages the tab 34 ofthe fin 20, 30. Alternatively, the bulging portion may be designed toprotrude outwardly relative to the truly circular portion of the cam 80.For example, the bulging portion may have an oval shape to make itbetter fit with the tab 34 of the fin 20, 30. The phrase “bulgingportion” used herein therefore means the portion of the cam 80 which isaligned with and engages the tab 34, whether it is substantiallycircular or alternatively, oval or protruding relative to the trulycircular part of the cam.

[0052] The cam 80 rotates smoothly on its axle 87 (FIG. 7) within thebearing 46 relative to its horizontal axis, and has a stopper 88 on eachend of the cam. The bearing 46 has a shape that is substantially similarto that of the cam 80 and is also shaped to receive the stoppers 88 andthe axle 87 (FIG. 7) located in each end of the cam 80. The fin plugassembly 24 is designed so that an engaging position is achieved byturning the worm gear 62 in a pre-selected direction, i.e., clockwise inthe embodiment shown in FIGS. 2 and 4, and a disengaging position isachieved by turning the worm gear 62 in the opposite direction, i.e.counter clockwise. Given the relative configuration of the worm gear 62and the cam 80, clockwise rotation causes the cam 80 to engage the tab34 of the fin 20, 30 with both a horizontal and vertical force thuspulling the tab 34 down into the cavity 40 and increasing the integrityof the engagement of the fin 20, 30.

[0053]FIG. 4 illustrates how the cam 80 is rotated to the engagingposition by turning the worm gear 62. In the engaging position, thebulging portion 86 of the cam 80 abuts a side surface 35 of the tab 34of the fin 20, 30, and creates sufficient friction to prevent the finfrom moving or dislodging. When the cam 80 is rotated to the disengagingposition, the flat portion 84 is aligned with the side surface of thetab 34, and this allows easy removal/insertion of the fin from/into thecavity 40 and fore/aft adjustment of the position of the fin 20, 30 inthe cavity 40. Thus, the present fin plug assembly is designed toreceive and secure the fin by controlling the rotation of the cam 80 andaligning the tab 34 of the fin with either the bulging portion 86 or theflat portion 84 of the cam 88. Unlike other known systems, the cam 80 isnot designed to extend forward or retract backward to bear against thetab 34 to secure the fin.

[0054] The fin plug assembly 24 may be made of a relatively hard plasticor other similar material well known in the art. Preferably, the cam 80and the worm gear 62 are made of a harder material, i.e. engineeringgrade plastic, which is less susceptible to distortion, twist, bending,or chipping.

[0055] Because both the cam 80 and the tab 34 are relatively hard, itmay be desirable to incorporate softer, malleable rubber materials oncertain areas of the tab 34 and/or the bulging portion 86 of the cam 80to create a more versatile friction fit. By incorporating certain rubbermaterials, when the cam 80 is rotated to the engaging position, thefriction between the bulging portion 86 and the tab 34 may be increasedor decreased to provide a more or less secure fit as desired or providea desired controlled friction. In other words, the malleable rubbermaterial incorporated in the tab 34 and/or the cam 80 allows flexibilityand control over the friction desired between the tab 34 and the cam 80,and the force required to cause the fin to be pulled from the fin plugassembly under sudden impacts may also be controlled.

[0056]FIG. 5 is a cross sectional view of the fin plug assembly 24according to another embodiment of the present invention. The cam 80 isrotated to the engaging position in FIG. 5 so that the bulging portion86 is received in a concave portion 36 of the tab 34. The concaveportion 36 on the tab 34 has a substantially curved shape and isdesigned to receive and bear against the bulging portion 86 of the cam80. Alternatively, as shown in FIG. 6, the tab 34 may include a cut outportion 38 which is designed to receive the bulging portion 86 of thecam 80. The embodiment shown in FIG. 6 allows greater flexibility in thealignment of the tab 34 and the cam 80.

[0057] In summary, shown in FIGS. 1-6 is a surf fin plug assembly 24 inwhich turning the worm gear 62 in one direction allows the bulgingportion 86 of the cam 80 to align with and engage the tab 34 and securethe fin which is inserted into the cavity 40, while turning the wormgear 62 in the opposite direction allows the flat portion 84 of the cam80 to align with and disengage the tab 34 for removal or adjustment ofthe fin.

[0058] The fin plug assembly 24 may be used for both the side fins 20and the rear fin 30. However, the fin plug assembly 24 used for the rearfin 30 may be larger to allow a greater fore-aft movement of the rearfin 30. In addition, as described in more detail below, the fin plugassembly 24 used for the side fins 20 may have a vertical built-in tiltangle while the fin plug assembly 24 for the rear fin 30 preferably doesnot.

[0059]FIG. 7 illustrates more clearly the positioning and relationshipbetween the worm gear 62, the cam 80, and the cavity 40 of the fin plugassembly 24. The cam 80 on each of the two ends has an axle 87 and thestopper 88. The cam 80 also has a plurality of teeth or gears 82 whichare designed to fit with the gears of the worm gear 62. By turning theworm gear 62 in one direction, i.e., clockwise, the cam 80 is rotated toengage the bulging portion of cam 80 against the tab 34 of the finreceived in the cavity 40. The worm gear 62 has the slot 64 which issubstantially rectangular to receive a specially designed key, ascrewdriver, a car or house key or other similarly shaped device. Theslot 64 of the worm gear 62 may be of any appropriate shape. The finplug assembly 24 of the present invention also allows a gradualtightening or adjustment of the fin by turning the worm gear 62 onlypartially or to the point of the desired tension.

[0060] As shown in FIGS. 1 and 7, the fin 20, 30 generally has a bodyportion and a mounting portion. The body portion defines a hydrodynamicfoil and is configured to extend generally perpendicularly relative tothe lower surface 26 of the surfboard 22. The mounting portion isattached to the body portion and is configured to be received andfrictionally held in the cavity 40 of the fin plug assembly 24. Themounting portion preferably includes at least one tab 34 and mayincorporate malleable rubber materials to control the friction betweenthe tab 34 and an engaging means, i.e., the cam 80, of the fin plugassembly 24.

[0061] Described now is the installation process of fin plug assembliesusing a complete control jig system 90 according to the presentinvention. Typically, installation of the fin plug assemblies known inthe art requires multiple marking and positioning jigs or templates andother tools and accessories, i.e. putty, tape, foam, center punch, etc.In addition, the conventional installation methods require multiplesteps of marking, positioning, removal, and repositioning of the jigs ortemplates that are often difficult, inaccurate, and time-consuming. Thecomplete control jig system 90 of the present invention allows an easy,quick, and accurate installation of fin plug assemblies.

[0062]FIGS. 8 and 9 illustrate by way of example a complete control jigsystem 90 and a method of installing the fin plug assembly using thecomplete control jig system 90. FIG. 8 shows the complete jig system 90having a pre-cut center portion 92 which is substantially the same shapeas the fin plug assembly to be installed. For the purpose ofillustration, the fin plug assembly to be installed is the assemblyshown in FIGS. 1-7 and described above.

[0063] The complete control jig system 90 is used to install the finplug assembly generally utilizing the following process. Before thecomplete control jig system 90 is placed on the lower surface 26 of thesurfboard 22, the surface area where the fin plug assembly is to beinstalled is generally sanded. Then, marks are made on the surfacemarking the spots where the front and rear ends of the fin will be afterthe fin plug assembly is installed, and a line 94 is drawn through themarks. FIGS. 8 and 9 illustrate the positioning of the complete controljig system 90 for a side fin plug assembly. Once the line 94 is drawn, apeel-off cover 96 on the bottom of the complete control jig system 90 isremoved, preferably exposing a self-adhesive surface, and the completecontrol jig system 90 is positioned along the line 94 as shown in FIGS.8-9. The bottom portion of the complete control jig system 90 includesglues, and is positioned on the lower surface 26 of the surfboard 22.When placed on the lower surface 26 of the surfboard 22, the centerportion 92 is removed from the complete control jig system 90.

[0064] Once the complete control jig system 90 is properly placed on thelower surface 26 of the surfboard 22 and the center portion 92 isremoved, a drill with a hole-cutting device, router or other cuttingdevice is used to create a mounting cavity 98 within the surfboard 22.The complete control jig system 90 is designed to guide the drill,router or other cutting device as it is moved around forming themounting cavity 98. Once the mounting cavity 98 is formed, depth cutouts 97 are removed from the complete control jig system 90 and the surffin plug assembly 24 as shown in FIG. 7 is positioned within themounting cavity 98The depth cut outs 97 are removed from the completecontrol jig system 90 so that the outriggers 66 (in FIG. 7) of the finplug assembly 24 are properly aligned and touching the lower surface 26of the surfboard 22. The temporary supports or outriggers 66 locate thefin plug assembly 24 at the appropriate height relative to thesurrounding surface of the surfboard. Preferably, a dummy fin (notshown) may be fitted into the fin plug assembly 24 before the fin plugassembly is positioned into the mounting cavity 98 to insure the properpositioning and installation of the fin plug assembly 24.

[0065] Once the fin plug assembly 24 is properly aligned and positionedwithin the mounting cavity 98, the space between the fin plug assembly24 and the mounting cavity 98 within the surfboard 22 is slowly filledwith a resin or other hardenable material well known in the art. Thecomplete control jig system 90 is preferably high enough to act as a damto contain the liquid resin or other hardenable material fromoverflowing. After the resin or hardenable material has set, thecomplete control jig system 90, the outriggers 66 and the collar 72 (inFIG. 3) of the fin plug assembly 24 are then sanded off so that the topsurface 74 of the fin plug assembly 24 is substantially flush with thelower surface 26 of the surfboard 22. The complete control jig systemshould thus be made of materials suitable for removal by sanding.

[0066] Also, as illustrated by a way of example in FIG. 11, the foammaterial 99 in the body of the surfboard 22, particularly the materialextending from the mounting cavity 98 may be further removed to provideadditional space 100 for resin or other hardenable material to enter,thereby increasing the stability of the fin plug assembly 24 installed.In one embodiment, a hand tool or other cutting device well known in theart may be used to remove material from a region extending from the base(which is indicated by a dotted line in FIG. 11) of the mounting cavity98 substantially to the skin, typically fiber-glassed, of an uppersurface 25 of the surfboard 22. This space 100 is filled with resin orother hardenable material to provide greater structural strength andstability to the fin plug assembly 24 which is installed in thesurfboard 22.

[0067] Alternatively, a spiking tool may be used to spike material fromregions extending from the side and/or the base of the mounting cavity98 to create additional space for resin or other hardening material toenter. Such space 102, 104 may extend vertically or at an angle as shownin FIG. 11, and when a spiking tool is used, the foam material aroundthe spiked point is also compressed and the compressed foam material 101provides additional structural support. If needed, the space 102 createdby the spiking tool can substantially touch to the skin, typically thefiber-glassed, of the upper surface 25 of the surfboard 22.

[0068] The complete control jig system 90 of the present invention alsoallows an easy adjustment of the tilt angle for the fins. As discussedabove, it may be desirable for the fins to have a vertical tilt angle.Typically, the side fins are vertically tilted toward the outwardlydirection at about 4°. The term “outwardly” used herein refers to thedirection opposite to the center portion of the surfboard 22. The rearfin 30 usually does not require a tilt angle. To accommodate the desiredtilt angle for the side fins, the fin plug assembly 24 for the side fins20 according to the present invention has a built-in tilt angle,typically 3°-5°, and preferably 4°.

[0069] If it is desirable to have a tilt angle greater than 3°-5°, asmall amount of putty may be pushed into the depth cut outs 97 of thecomplete control jig system 90. The fin plug assembly 80 can now betilted using the putty to control the depth of the outriggers 66.

[0070] The complete control jig system 90 controls and guides theinstallation of fin plug assemblies 24. The installation processutilizing the complete control jig assembly 90 of the present inventionis easy, accurate and less time consuming, and provides a significantimprovement compared to other conventional systems.

[0071]FIG. 10 is an exemplary view illustrating how multiple units ofthe fin plug assembly 24 according to the present invention may be usedto fix the fin 30 with multiple tabs 34. Shown in FIG. 10 are two finplug assemblies, 24 embedded within the surfboard 22. The arrangementshown in FIG. 10 is particularly useful for securing larger rear finswhich require greater anchoring. The rear fin 30 in FIG. 10 has two tabs34, and each tab 34 may be inserted and secured into a separate fin plugassembly 24. Alternatively, each fin plug assembly 24 may also receiveone and more tabs 34.

[0072]FIG. 12 illustrates a cross sectional view of the fin plugassembly 24 where the tab 34 has an undercut 100 that cuts into a firstside 102 of the tab 34 at a predetermined position 104 and terminates ina slopping angle at the base 106 of the tab 34. The undercut 100 mayform an angle θ1 with the vertical line 108. The angle 01 may varydepending on the contour of the bulging portion 86 of the cam 80. Theangle θ1 may be set so that as the cam 80 rotates in a counter-clockwisedirection, the bulging portion 86 engages with the undercut 100 to pulldown the tab 34 into the cavity 40 until the tab is securely held inplace. The angle θ1 may be about 5° and about 45°. One of the advantagesof having an undercut 100 to engage with the cam 80 is that the bulgingportion 86 may engage with any portion of the undercut 100 between thepredetermined position 104 and the base 106 to ensure that the tabsecurely engages within the cavity 40.

[0073]FIG. 13 illustrates the tab 34 having an undercut 110 thatterminates above the base 106. This way the undercut angle θ2 may begreater than θ1 as shown in FIG. 12 without having to cut deep into thefirst side wall 102 along the predetermined position 104. Having theundercut at a steeper angle may allow the bulging portion to engagebetter with the undercut.

[0074]FIG. 14 illustrates a side view of a fin with a tab 34 extendingfrom the end surface 32. As further illustrated in FIG. 15, the tab 34may have the first side 102 and a second side 112, where the first side102 engages with the cam 80 and the second side 112 engages with a sidewall 114 formed within the cavity 40 as illustrated in FIG. 16. Thesecond side 112 and the sidewall 114 may have corrugation 111 toassociate with each other so that when the worm gear 62 is activated thecorrugated second side 112 may flush against the corrugated sidewall 114within the cavity as illustrated in FIG. 17. With the second side 112and the side wall 114 being both corrugated, the tab 34 may besubstantially locked in place from back forth movement along thelongitudinal axis of the tab, and substantially prevented from beingpulled out of the cavity when the side fin or the rear of the finaccidentally hits a rock or an impending object during surfing.Alternatively, either the sidewall 114 or the second side 112 may becorrugated, but not both sides.

[0075] FIGS. 18-20 illustrated that certain portions of the second sidemay be corrugated rather than being substantially corrugated along theentire second side 112. For example, FIG. 18 illustrated that thecorrugation may be formed on the forward sides 116 of the tab 34. FIG.19 illustrates that the corrugation may be formed on the rear side 118of the tab 34. FIG. 20 illustrates that corrugation may be formed bothon the forward side 116 and the rear side 118 but not on the centerportion of the tab 34. FIG. 21 illustrates that the corrugation may runalong the longitudinal access 120 of the fin 34 rather than verticallyas illustrated in FIG. 14. In such a case, the sidewall 114 within thecavity 40 may also be corrugated to match the corrugation that is formedalong the longitude and the access of the tab 34. The corrugation mayhave a variety of shapes such as a sinusoidal configuration asillustrated in FIG. 15. Alternatively, corrugation may have triangle andrectangle shapes. For example, as further illustrated in FIG. 22, thecorrugation between the side wall 114 and the second side 112 may engageso that the fin does not get removed from the cavity due to any bendingforce on the fin caused by the fin hitting a rock for example.

[0076]FIG. 23 illustrates another fin plug assembly 200 that includes aworm gear 62 position adjacent to the cavity 40 formed within the finplug assembly 200. The worm gear 62 may have teeth that protrudes intothe cavity 40 that is adapted to engage with thread 206 formed on thefirst side 102 of the tab 34. In this embodiment, as the worm gear 62 isactuated by rotation for example, the teeth 68 engages with the thread206 to secure the tab 34 within the cavity 40 of the assembly 200. Withthe fin plug assembly 24, the need for the cam may be eliminated.

[0077]FIG. 24 illustrates a fin plug assembly 24 including a worm gear302 that has teeth 304 adapted to associate with an undercut 306 form onthe first side 102 of the tab 34. Teeth 304 may have a pitch angle thatincreases as the worm gear 302 is rotated so that as the worm gear isrotated in a certain direction, the thread 304 pushes down on theundercut 306 to secure the tab 34 within the cavity 40. As illustratedin FIG. 24, to insert the tab 34 into the cavity 40, the worm gear 302may be positioned so that the teeth 304 has a pitch angle α1 facing theundercut 306. And as the worm gear 302 is rotated to engage the tab 34within the cavity 40, the pitch angel increases until the pitch angle α2engages with the undercut 306. The rotation action of the worm gear 302may draw the tab 34 into the cavity because of the downward force of theteeth 304 on the undercut 306 as the pitch angle increases. When theworm gear 302 is rotated so that it is fully engaged, the pitch angle α2may be substantially equal to the angle θ3 formed on the undercut 306 sothat the surface area of the teeth 304 substantially engage the surfacearea of the undercut 306.

[0078] Having thus described different embodiments of the invention,other variations and embodiments that do not depart from the spirit ofthe invention will become readily apparent to those skilled in the art.The scope of the present invention is thus not limited to any oneparticular embodiment, but is instead set forth in the appended claimsand the legal equivalents thereof.

What is claimed is:
 1. A system for releasably securing a tab of a fin,comprising: a fin plug assembly having a cavity adapted to receive a tabextending from a fin; a worm gear having teeth adapted to rotate withinthe fin plug assembly; a cam between the worm gear and the cavity, wherethe cam is adapted to engage with the teeth of the worm gear such thatrotation of the worm gear causes the cam to engage with the tab of thefin within the cavity.
 2. The system according to claim 1, where the tabhas a first side with a sloping undercut adapted to engage with the cam,where rotation of the worm gear causes the cam to engage with thesloping undercut to secure the tab within the cavity of the fin plugassembly.
 3. The system according to claim 1, where counter rotation ofthe worm gear causes the cam to release the sloping undercut of the tabwithin the cavity.
 4. The system according to claim 2, where the slopingundercut extends to a base of the tab.
 5. The system according to claim2, where the sloping undercut terminates above a base of the tab.
 6. Thesystem according to claim 1, where the tab has a second side, where atleast a portion of the second side is corrugated, where the cavity has aside wall adapted to associate with the second side of the tab that iscorrugated.
 7. The system according to claim 6, where the portion of thesecond side of the tab this is corrugated is on a front portion.
 8. Thesystem according to claim 6, where the portion of the second side of thetab this is corrugated is on a back portion.
 9. The system according toclaim 6, where the portion of the second side of the tab this iscorrugated is on a middle portion.
 10. The system according to claim 6,where the portion of the second side of the tab this is corrugated issubstantially the second side.
 11. The system according to claim 6,where the second side is corrugated to form a sine wave.
 12. The systemaccording to claim 6, where the second side is to form a saw-toothconfiguration.
 13. A system for engaging a fin to a surfboard,comprising: a worm gear having teeth adapted to be actuated within a finplug assembly that has a cavity adapted to receive a tab extending froma fin, where actuation of the worm gear causes the tab to be securedwithin the cavity.
 14. The system according to claim 13, furtherincluding a cam between the tab and the worm gear, where the cam haveteeth to engage with the teeth of the worm gear.
 15. A system forengaging a fin to a surfboard, comprising: a worm gear having teethadapted to actuate within a fin plug assembly; and a tab having a firstside adapted to engage with the teeth of the worm gear, where rotationof the worm gear causes the tab to secure within the cavity.
 16. Thesystem according to claim 15, where the first side of the tab has athread that engages with the teeth of the worm gear that causes the tabto secure within the cavity with the rotation of the worm gear.
 17. Thesystem according to claim 15, where the first side of the tab has anundercut that engages with the teeth of the worm gear that causes thetab to secure within the cavity with the rotation of the worm gear. 18.The system according to claim 17, where the teeth has a pitch angle thatincreases with rotation of the worm gear to engage the undercut on thefirst side of the tab to secure the tab within the cavity with therotation of the worm gear.
 19. The system according to claim 15, wherethe longitudinal axis of the worm gear is substantially parallel withthe longitudinal axis of the tab.
 20. The system according to claim 15,where a counter-rotation of the worm gear causes the tab to be releasedfrom the cavity.
 21. A fin for a surf board, comprising: a tab extendingfrom a fin, where the tab has first side with a sloping undercut adaptedto engage with a fin plug assembly.
 22. The fin according to claim 21,where the tab has a second side, where at least a portion of the secondside is corrugated adapted to associate with a sidewall formed within acavity.
 23. The fin according to claim 22, where the portion of thesecond side of the tab that is corrugated is on a front portion.
 24. Thesystem according to claim 22, where the portion of the second side ofthe tab that is corrugated is on a back portion.
 25. The systemaccording to claim 22, where the portion of the second side of the tabthat is corrugated is on a middle portion.
 26. The system according toclaim 22, where the portion of the second side of the tab that iscorrugated is substantially the second side.
 27. The system according toclaim 22, where the second side is corrugated to form a sine wave. 28.The system according to claim 22, where the second side is corrugated toform a saw-tooth configuration.
 29. A system for engaging a fin for asurfboard, comprising: a worm gear having teeth adapted to actuate in afin plug assembly that has a cavity adapted to receive a tab extendingfrom a fin; and a cam between the worm gear and the cavity, where thecam is adapted so that actuation of the worm gear causes the cam toengage with the tab from the fin.
 30. The system according to claim 29,where the cam has teeth to engage with the teeth of the worm gear.
 31. Amethod for engaging a fin to a surfboard, comprising: forming a tabprotruding from a fin for a surfboard; inserting the tab into a cavityformed within a plug assembly formed within a surfboard; and engaging aside of the tab within the plug assembly to secure the fin to thesurfboard.
 32. The method according to claim 31, further including:undercutting the side of the tab to engage with a cam within the plugassembly; and actuating a worm gear that causes the cam to engage withthe undercutting.
 33. The method according to claim 31, furtherincluding: threading the side of the tab; actuating the worm gear thathas teeth; and engaging the teeth of the worm gear to the threading tohold the tab within the cavity.
 34. The method according the claim 31,further including: undercutting the side of the tab; increasing a pitchangle of a teeth on a worm gear; rotating the worm gear to engaging theteeth with the undercutting on the side of tab to engage the tab withinthe plug assembly.